Gonorrhea is a common STI caused by bacteria. Some people with gonorrhea will experience pain while urinating or discharge, but many will have no symptoms.

Gonorrhea is easily treated with antibiotics. If gonorrhea is left untreated, it could affect a person’s fertility or spread to a partner.

Hepatitis B is a virus that can spread via sex, and can cause liver infection and inflammation. Some people with hep B will have abdominal pain, fever, or fatigue, but many will have no symptoms.

Hepatitis B can’t be cured with antibiotics, but about 95% of people infected with the virus will recover on their own in 4–8 weeks. In rare cases, people can become hep B “carriers,” with long-term contagious infections.

Sperm concentration is the number of sperm per milliliter of semen. This number helps us compare your sample to others.

A hepatitis C antibody test will tell you if you’ve ever had a hep C infection. If you test positive, you’ll need an additional test to measure the amount of hepatitis C virus in your blood. Hepatitis C can typically be treated with antiviral medications. If hep C is left untreated, it can cause damage to the liver or spread to other people.

HIV (human immunodeficiency virus) is a virus that can spread via sex. Some people with HIV will have temporary flu-like symptoms, while others will have no symptoms.

HIV affects the immune system and can reduce a person’s ability to fight off infections. HIV can’t be cured with antibiotics, but antiviral medication can reduce symptoms and the chance of spreading HIV. If HIV is left untreated, it could develop into AIDS, a disease of the immune system.

Syphilis is a common STI caused by bacteria. Some people with syphilis will experience genital sores, but some will have no symptoms.

Syphilis is easily treated with antibiotics. If syphilis is left untreated, it could affect a person’s fertility, spread to a partner, or have wide-ranging impacts on the body and brain.